Re: [PATCH] tty: serial: return appropriate error on failure

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Dec 08, 2021 at 03:47:41AM +0530, Vihas Mak wrote:
> when a user with CAP_SYS_ADMIN disabled calls ioctl (TIOCSSERIAL),
> uart_set_info() returns 0 instead of -EPERM and the user remains unware
> about what went wrong. Fix this.
> 
> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215205
> 
> Signed-off-by: Vihas Mak <makvihas@gmail.com>
> ---
>  drivers/tty/serial/serial_core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
> index 61e3dd022..c204bdecc 100644
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -960,7 +960,7 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
>  		uport->fifosize = new_info->xmit_fifo_size;
>  
>   check_and_exit:
> -	retval = 0;
> +	retval = retval < 0 ? retval : 0;

Please no, do not use ? : unless you have to.  Spell it out and use a
real if statement.

thanks,

greg k-h